Journal of the American Ceramic Society, Vol.102, No.9, 5668-5678, 2019
Fine-grained 3C-SiC thick films prepared via hybrid laser chemical vapor deposition
An ultraviolet laser (lambda=266nm) operated in pulsed mode and a diode laser (lambda=1060nm) operated in continuous mode were simultaneously applied to create a hybrid laser chemical vapor deposition (CVD) approach. Fine-grained 3C-SiC thick films were prepared via hybrid laser CVD by using SiCl4, CH4 and H-2 as precursors. The effects of the ultraviolet laser on the preferred orientations, microstructures, microhardness values and deposition rates of 3C-SiC thick films were investigated. The 3C-SiC thick films that were prepared at 4kPa via diode laser CVD exhibited < 110 >-orientations and 5-100 mu m grain sizes, whereas those prepared via hybrid laser CVD were randomly oriented with 0.5-5 mu m grain sizes. Compared to diode laser CVD, the additional irradiation of the ultraviolet laser in the hybrid laser CVD improved the Vickers microhardness values of the 3C-SiC thick films from 30 to 35GPa, and the maximum deposition rate was also increased from 935 to 1230 mu m/h.